tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1Kernel driver occ-hwmon
2=======================
3
4Supported chips:
5 * POWER8
6 * POWER9
7
8Author: Eddie James <eajames@linux.ibm.com>
9
10Description
11-----------
12
13This driver supports hardware monitoring for the On-Chip Controller (OCC)
14embedded on POWER processors. The OCC is a device that collects and aggregates
15sensor data from the processor and the system. The OCC can provide the raw
16sensor data as well as perform thermal and power management on the system.
17
18The P8 version of this driver is a client driver of I2C. It may be probed
19manually if an "ibm,p8-occ-hwmon" compatible device is found under the
20appropriate I2C bus node in the device-tree.
21
22The P9 version of this driver is a client driver of the FSI-based OCC driver.
23It will be probed automatically by the FSI-based OCC driver.
24
25Sysfs entries
26-------------
27
28The following attributes are supported. All attributes are read-only unless
29specified.
30
31The OCC sensor ID is an integer that represents the unique identifier of the
32sensor with respect to the OCC. For example, a temperature sensor for the third
33DIMM slot in the system may have a sensor ID of 7. This mapping is unavailable
34to the device driver, which must therefore export the sensor ID as-is.
35
36Some entries are only present with certain OCC sensor versions or only on
37certain OCCs in the system. The version number is not exported to the user
38but can be inferred.
39
40temp[1-n]_label OCC sensor ID.
41[with temperature sensor version 1]
42 temp[1-n]_input Measured temperature of the component in millidegrees
43 Celsius.
44[with temperature sensor version >= 2]
45 temp[1-n]_type The FRU (Field Replaceable Unit) type
46 (represented by an integer) for the component
47 that this sensor measures.
48 temp[1-n]_fault Temperature sensor fault boolean; 1 to indicate
49 that a fault is present or 0 to indicate that
50 no fault is present.
51 [with type == 3 (FRU type is VRM)]
52 temp[1-n]_alarm VRM temperature alarm boolean; 1 to indicate
53 alarm, 0 to indicate no alarm
54 [else]
55 temp[1-n]_input Measured temperature of the component in
56 millidegrees Celsius.
57
58freq[1-n]_label OCC sensor ID.
59freq[1-n]_input Measured frequency of the component in MHz.
60
61power[1-n]_input Latest measured power reading of the component in
62 microwatts.
63power[1-n]_average Average power of the component in microwatts.
64power[1-n]_average_interval The amount of time over which the power average
65 was taken in microseconds.
66[with power sensor version < 2]
67 power[1-n]_label OCC sensor ID.
68[with power sensor version >= 2]
69 power[1-n]_label OCC sensor ID + function ID + channel in the form
70 of a string, delimited by underscores, i.e. "0_15_1".
71 Both the function ID and channel are integers that
72 further identify the power sensor.
73[with power sensor version 0xa0]
74 power[1-n]_label OCC sensor ID + sensor type in the form of a string,
75 delimited by an underscore, i.e. "0_system". Sensor
76 type will be one of "system", "proc", "vdd" or "vdn".
77 For this sensor version, OCC sensor ID will be the same
78 for all power sensors.
79[present only on "master" OCC; represents the whole system power; only one of
80 this type of power sensor will be present]
81 power[1-n]_label "system"
82 power[1-n]_input Latest system output power in microwatts.
83 power[1-n]_cap Current system power cap in microwatts.
84 power[1-n]_cap_not_redundant System power cap in microwatts when
85 there is not redundant power.
86 power[1-n]_cap_max Maximum power cap that the OCC can enforce in
87 microwatts.
88 power[1-n]_cap_min Minimum power cap that the OCC can enforce in
89 microwatts.
90 power[1-n]_cap_user The power cap set by the user, in microwatts.
91 This attribute will return 0 if no user power
92 cap has been set. This attribute is read-write,
93 but writing any precision below watts will be
94 ignored, i.e. requesting a power cap of
95 500900000 microwatts will result in a power cap
96 request of 500 watts.
97 [with caps sensor version > 1]
98 power[1-n]_cap_user_source Indicates how the user power cap was
99 set. This is an integer that maps to
100 system or firmware components that can
101 set the user power cap.
102
103The following "extn" sensors are exported as a way for the OCC to provide data
104that doesn't fit anywhere else. The meaning of these sensors is entirely
105dependent on their data, and cannot be statically defined.
106
107extn[1-n]_label ASCII ID or OCC sensor ID.
108extn[1-n]_flags This is one byte hexadecimal value. Bit 7 indicates the
109 type of the label attribute; 1 for sensor ID, 0 for
110 ASCII ID. Other bits are reserved.
111extn[1-n]_input 6 bytes of hexadecimal data, with a meaning defined by
112 the sensor ID.